Atmospheric Chemistry Models (IMAGE) University of Massachusetts Amherst Caption Young pine trees are overshadowed by mature oaks, reflecting the mixed, segregated nature of this forest. Atmospheric chemistry models in use now may underestimate the importance of tree species mix and size to ozone pollution. Credit UMass Amherst/Alexander Bryan Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.